1. Technical Field
The present invention relates to an electric bed, and more particularly, to a method of controlling rotational speed of a motor of an electric bed.
2. Description of Related Art
In general, an electric bed includes at least one movable bed plate, a fixed bed frame and an actuator. The movable bed plate is rotatably connected with the fixed bed frame, and the actuator is connected between the movable bed plate and the fixed bed frame to drive the movable bed plate to swing relative to the fixed bed frame. The actuator includes a motor to serve as a source of a motive force which must produce so high rotational speed as to overcome the load the actuator bears, and the load includes the mechanical resistance of the electric bed and the weight of the user. Because the electric beds have unequal mechanical resistances and the users thereof are of unequal weight, the motors of the electric beds even having the same specification still rotate in different speeds, which brings the users different usage experiences so as to reduce the users' trust in the quality of the electric bed. In addition, the double electric bed includes two electric single beds, the movable bed plates of which are driven by two motors, respectively. If the rotational speeds of the two motors are unequal to each other, the movable bed plates can not swing synchronously, which makes the motion of the double electric bed look not fine but rough so that the double electric bed is hard to impress and attract the user.